SAUTE: Heat 2 tablespoons of butter or olive oil in the instant pot on the sauté setting. Add the onions and carrots and sauté until the onions just barely start to brown, about 9-10 minutes. Add the potatoes, lentils, tomato paste, 5 cups of broth, turmeric, and if desired, 1/4 teaspoon cayenne pepper. Cover the Instant Pot, hit the bean/chili button and adjust the pressure time. 10 minutes for yellow lentils, 13-15 minutes or split peas depending on how old they are. Once the timer goes off, turn the knob to vent.

BLEND: Using a hand blender or by transferring the soup to a traditional blender, blend the soup completely. You may need additional broth to thin the soup out. I ended up using 1 additional cup to blend/thin soup to my liking. But note that the soup will thicken as it sits, to make sure you have a little extra broth or add water.

FINISH: Adjust salt to taste and stir in the remaining 2 tablespoons of butter. You can also add additional cayenne if you prefer spicier soups. Feel free to serve with lemon wedges and tons of chopped parsley. I go back and forth on the lemon wedge, love it with it, love it without it!